Telephony users have long had to deal with a proliferation of user devices (sometimes referred to as ‘user equipment’ or ‘endpoints’) through which third parties may contact them. For example, a user might have a fixed-line (or ‘wireline’) telephony device for use at home, a further fixed-line telephony device for use in the office, and a mobile telephony device for use whilst on the move. Each type of telephony device has associated advantages; whilst a mobile telephony device provides the user with mobility, a fixed-line telephony device can provide more reliable communications with no battery recharge concerns.
Users may also have a number of different access technologies available through which their telephony devices may conduct communications. For example, one of the user's telephony devices may be equipped with a circuit-switched communication interface for conducting communications via suitable circuit-switched networks and the same or another of the user's telephony devices may be equipped with a packet-switched communication interface for communicating via suitable packet-switched networks.
A circuit-switched telephony device may comprise a fixed-line Plain Old Telephone Service (POTS) telephone equipped with a circuit-switched interface and communication client for conducting communications via a Public Switched Telephone Network (PSTN). A circuit-switched telephony user device may comprise a mobile (or ‘cellular’) telephone equipped with a wireless circuit-switched interface and communication client for conducting communications via a cellular network such as a Global System for Mobile Communications (GSM) network or Code Division Multiple Access (CDMA) network.
More recently, packet-switched telephony devices have proliferated which may take the form of a fixed-line Internet Protocol (IP) telephone equipped with a fixed-line packet-switched interface and communication client for communicating via an Internet Protocol (IP) network, such as the Internet or an IP Private Branch Exchange (IP-PBX). Similarly, a user may conduct communications via a personal computer (PC) equipped with a packet-switched communication client for conducting communications over the Internet via a fixed-line Internet connection. A mobile packet-switched telephony device may take the form of a portable computing device, such as a laptop or tablet, equipped with a wireless packet-switched interface and communication client for communicating via an IP network, such as the Internet, using a WiFi™ or Bluetooth™ compliant wireless access point. A packet-switched communication client may conduct communications according to an Internet telephony protocol, commonly referred to as Voice over Internet Protocol (VoIP), with associated setup and/or control protocols such as the Session Initiation Protocol (SIP) or H.323.
Increasingly, telephony user devices are available that are equipped with multiple communication interfaces to facilitate communication via multiple access technologies. For example, a modern “smartphone” is typically equipped with a circuit-switched interface for communicating via a cellular network and a packet-switched interface for communicating via the Internet. Commonly, a smartphone may be equipped with several packet-switched interfaces, for example, a short-range radio interface, e.g. WiFi or Bluetooth™ compliant, and/or an interface for communication of packet data through a cellular network, such as 3rd Generation Partnership Project (3GPP) Long Term Evolution (LTE), LTE-Advanced (LTE-A), High Speed Packet Access (HSPA), Wideband Code Division Multiple Access (W-CDMA) or Mobile WiMax etc. In such cases, a packet-switched communication client may also be deployed for conducting communications via one or more of the available wireless packet-switched interfaces. In cases such as this where a device is equipped with more than one communication client, the various clients deployed in that device are referred to as co-located. A suitable packet-switched communication client may be deployed on a user equipment prior to sale, or could be deployed subsequently through an application distribution portal such as the Apple® App StoreSM or Android™ Market etc.
Taking an example of a smartphone that can conduct communications using WiFi access technology via a packet-switched network or cellular network access technology via a circuit-switched network, there are various reasons for wanting to connect phone calls involving the user over WiFi access, when available, rather than via cellular access. One reason is that a connection via WiFi may well offer better voice quality than via circuit-switched communications at any given location. Indeed, mobile users often suffer poor cellular coverage in locations where they often wish to use their cell phones and where WiFi coverage is good, including their home and their office. Another reason is that WiFi access may permit a better quality of user experience for a call by permitting the use of High Definition (HD) voice codecs and/or permitting the uplift of a voice call to include video. Yet another reason is that a user who is roaming outside their home network and is currently in a location with WiFi access may be able to make and receive calls via WiFi that do not attract additional roaming charges and, therefore, save the user money. Still another reason is that network operators may be able to benefit from reduced loading on their cellular Radio Access Network (RAN) infrastructure when subscribers connect voice calls over WiFi. One reason not to use WiFi access is because of possible data security concerns, particularly when using an unsecured or public WiFi connection.
With such a number of considerations to be taken into account when routing calls the user is sometimes left with a less than satisfactory experience when a call in which they are involved is routed in the network in an unsatisfactory manner.
It would therefore be desirable to provide improved routing of calls in a telecommunications network, particularly, but not exclusively, where this results in an improved user experience.